We analysed avian diversity in 8 similar-sized regions of Africa, and in an additional 16 regions spread across the world; half of these 24 regions were tropical and the other half were temperate. For each region, counts of species, genus, family and order were recorded rather than only a species count. We assert that this approach gives more accurate insights into diversity patterns, as we show that in relatively species-rich parts of the world species are on average taxonomically more similar to each other than in species-poor areas. Northwestern South America is the world's most species-rich region for birds, but we show that sub-Saharan Africa has greater diversity at higher taxonomic levels and is thus arguably the richest corner of the world for birds: the Mozambique-Zimbabwe region displays the highest diversity at the order level (with 30 orders), with all other sub-Saharan regions having between 27 and 29 orders each. Northern India is also extremely diverse (surprisingly so for a marginally temperate region) at all taxonomic levels below that of order. We hope that our study might generate further analyses of avian diversity beyond the species level.